reasonable response to the question, "Are human psychological characteristics the result of natural selection, or are none the result of natural selection" is "yes".
Somebody: It's precisely the role of science to probe beyond truisms like the above and determine the down-and-dirty specifics of gene function, epigenetics, social conditioning and how they *interact*. But you're closing off that pursuit by preemptively declaring any conclusions as "Just so" stories. That doesn't seem very fair minded to me.
Marx, on the other hand, was fair minded by and large:
"Darwin’s work is most important and suits my purpose in that it provides
a basis in natural science for the historical class struggle. One does,
of course, have to put up with the clumsy English style of argument. Despite all shortcomings, it is here that, for the first time, ‘teleology’ in natural science is not only dealt a mortal blow but its rational meaning is empirically explained."
By contrast, I feel like some of his followers would have responded to those "shortcomings" by rejecting the entire theory of natural selection as so much capitalist propaganda, were they alive in the mid 19th century.